In many current electronic and/or optoelectronic and/or electro-optic circuit arrangements, one or more semiconductor components ("semiconductor electronic devices")--such as semiconductor integrated circuit devices--are positioned on a leadframe structure. The leadframe structure, together with the one or more semiconductor electronic devices, is encased in an overmolded package, so as to form a single in-line package (SIP) or dual-in-line package (DIP) structure. The overmolded package typically is molded from a plastic to completely encase the one or more semiconductor electronic devices. Typically, electrical signals are transmitted to or from (or both to and from) the one or more semiconductor electronic devices located in the overmolded package via a supporting printed circuit board ("wiring board") and via a plurality of internal leadframe fingers that are electrically connected to the encased one or more semiconductor electronic devices by means of internal wirebonds--i.e., wirebonds that are themselves encased in the overmolded package. The circuit board has its own wiring located on an insulating board that physically supports the SIP or DIP structure. However, in some cases, an additional requirement arises, to provide a direct electrical contact between the one or more devices located internally to (inside of) the molded package and another device--such as an electronic device, an opto-electronic, an electro-optic, or a combination of them--located eternally to (outside of) the overmolded package, without passing through the wiring of the supporting circuit board (e.g., in situations where the amount of signal degradation, associated with signals passing through the circuit board wiring, would be unacceptable).
A problem associated with a direct wirebond between a device located externally to the package and a device located internally to the package is that an essentially clean wirebond contact on the overmolded package is required to provide both the necessary low-resistance electrical connection and the necessary mechanical integrity. However, inherent in the overmolding operation is a residue of molding compound (typically, a thermoset resin) that will adhere to the exposed wirebond surface. Conventional cleaning agents, which may be capable of removing the resin from the exposed gold wirebond pad sites, are not acceptable alternatives since they have been found to attack the overmolded package or the gold wirebond contact area (or both the package and the contact area), as well as require a one-at-a-time cleaning process (which is costly as compared to a "batch" cleaning system).
A need remains, therefore, for an arrangement capable of improving the electrical quality of wirebond or other electrically conductive wiring attachments to electronic devices located in molded packaging arrangements.